The present invention relates generally to evanescent-wave coupling devices and more particularly to evanescent-wave coupling devices which may be utilized to couple signals between a diode array and a dielectric waveguide.
Presently, a great deal of interest exists in the development of integrated circuits for use at microwave, millimeter and submillimeter frequencies. For example, "Dielectric Waveguide Microwave Integrated Circuits-An Overview", by Robert M. Knox, IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-24, No. 11, November 1976, presents a discussion of integrated circuit techniques for use at microwave and millimeter wavelengths using refractive-type waveguides and integrated circuit processing. The use of dielectric waveguides to transmit infrared energy has recently been developed and it is disclosed in "Polycrystaline Fiber Optical Waveguides for Infrared Transmission", by D. A. Pinnow et al, IEEE Journal of Quantum Electronics, QE-13, No. 9 (Sept. 19, 1977), page 91d, and a presently co-pending patent application entitled Millimeter Wave Transmission Line Using Thallium Bromoiodide Fiber, Ser. No. 90,233, filed Nov. 1, 1979, by Adrian E. Popa, now U.S. Pat. No. 4,293,833.
The coupling of such guided waves to microwave devices such as microwave mixer diodes, or the like, has generally been done in a number of ways. One such way is the so-called whisker contact method, wherein the end of a whisker-like wire antenna is butt-coupled to a diode in order to inject energy into or extract energy from the waveguide. Coupling to the whisker may be enhanced by means of a reflector arrangement wherein electromagnetic energy is directed at a reflector-type antenna which re-directs the electromagnetic energy onto the whisker. The diode is then utilized to down-convert the electromagnetic signal into an intermediate frequency signal utilized in a receiver system. Such a system is described in the article "High Sensitivity Submillimeter Heterodyne Receiver", by H. R. Fettermen et al, Proceedings of the IEEE, 1978.
Conventional microwave devices are well-known in the art, and are generally discussed in a book entitled "Microwave Semiconductor Devices and Their Circuit Applications", edited by H. A. Watson, McGraw-Hill Book Company 1969, with particular reference to chapters 8-12. Millimeter-wave integrated circuits are also discussed in a paper entitled "Millimeter-Wave IC's Spring From The Lab", by N. C. Deo et al, in Microwaves, October 1979.
However, no prior art systems have been designed which allow for the coupling of microwave energy between a dielectric waveguide and an array of diodes.
It would therefore be an improvement in the microwave art to provide for an evanescent-wave coupling device which allows coupling of microwave, millimeter or submillimeter wave energy between a dielectric waveguide and a diode array.
Also, it would be an improvement in the microwave art to provide an evanescent-wave coupler which may be employed as a harmonic generator, upconverter, mixer, signal source, detector arrangement, or power combiner, or the like.